27 July 2021: Image Quiz #61

Author: Bin Xu, M.D., Ph.D.

A 45 year old man presents with a nasal cavity mass. A representative H&E of the mass is shown in the picture. Which of the following statements is true?

Select an answer:

A. Differential diagnoses include adenoid cystic carcinoma of salivary gland origin and HPV related multiphenotypic sinonasal carcinoma

B. Tumor is consistently negative for myoepithelial markers, e.g. SMA, calponin and S100

C. Tumor may be positive for EBV

D. 80% are positive for EWSR1 fusion

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7 July 2021: Pathology Images of the Week

Here is a selection of new images from our free, online textbook:

CNS tumor > Papillary craniopharyngioma

Classic low power cauliflower-like configuration with smooth borders.

Contributed by Nelli S. Lakis M.D., M.Sc.

Nasal cavity, paranasal sinuses, nasopharynx > Sinonasal undifferentiated carcinoma

Sheets of undifferentiated malignant epithelial cells with vesicular nuclear chromatin and prominent nucleoli.

Contributed by Bin Xu, M.D., Ph.D. and Abeer Salama, M.D.

Placenta > Choriocarcinoma

Intraplacental choriocarcinoma showing atypical syncytiotrophoblast, cytotrophoblast and intermediate trophoblast adjacent to uninvolved chorionic villi (H&E, 200x).

Contributed by Tatyana Zinger, D.O.

Small intestine & ampulla > Heterotopic gastric mucosa

Polypoid lesion predominantly lined by gastric foveolar epithelium and small intestinal epithelium on the left side.

Contributed by Khalid Amin, M.D.

Liver & intrahepatic bile ducts > Hepatocellular adenoma

HNF1A mutated hepatocellular adenoma: low power view showing well defined border between the lesion (right) and background liver (left).

Contributed by Monica Abdelmalak, M.D.